Various arrangements have been proposed for selectively locking a first window sash against movement relative to an adjacent second window sash. In one arrangement commonly employed for locking residential double hung windows, a manually actuated pivotal locking member is mounted on the lower window sash and is effective to selectively engage a lock catch mounted on the upper window sash. While such an arrangement is mechanically effective for achieving its intended purpose, its appearance is aesthetically undesirable in modern settings since both the pivotal locking member and lock catch are exposed to view.
Other attempts have been made to create locks for double hung windows which are aesthetically pleasing. One such attempt, partially surrounds the locking mechanism so that the majority of the internal components which make up the locking mechanism are screened from view. However, even this locking mechanism includes components which are exposed to view which are not aesthetically pleasing. Another type of window lock for double hung windows achieves the result of substantially covering the locking mechanism with a cover when in the locked position, but fails to adequately cover the locking mechanism when in the unlocked position and when moving between the locked and unlocked positions. Accordingly, the conventional mechanisms for locking double hung windows have not been completely aesthetically pleasing and, therefore, a need has arisen for a window lock which securely locks a double hung window and yet has a completely aesthetically overall pleasing appearance.
Furthermore, even where conventional window locks achieve a somewhat aesthetically pleasing appearance, they fail to include any mechanism which would prevent a child from unlocking the window lock. It is well-recognized that windows which are installed at significant heights above ground level are dangerous to small children when in the open position. Therefore, a need has arisen for a window lock which is resistant to a small child opening it without adult supervision. Such a window lock would significantly decrease the chances of a small child falling from an open window which is located significantly above ground level.
The present invention provides a window lock for locking a first window sash to an adjacent second window sash. The lock includes and actuating lock casing which substantially surrounds the internal mechanisms of the lock and is capable of linear reciprocal movement to control the lock. Since the lock casing substantially surrounds the internal components of the lock, it provides the lock with an overall aesthetically pleasing appearance. The present invention also includes a safety mechanism which assists in maintaining the window lock in the locked position.